How To Check Your Driveshaft For Bad Carrier Bearings and U-Joints
Carrier bearings. also known as center support bearings, or center bearings, are supports for your driveshaft. When these parts go bad, you can feel it. You’ll notice vibrations under your car or truck when you’re accelerating, and you might also hear grinding or screeching.
Symptoms like the above can’t be ignored, you’ll have to check your carrier bearings and your u-joints for damage. To help, we’ll go more into detail about the symptoms of bad carrier bearings, why these parts go bad, and how you can inspect your vehicle for these problems on your own.
Symptoms of Bad Carrier Bearings and U-Joints:
1. Your Car’s Vibrating While You Accelerate
Your driveshaft’s carrier bearing can loosen and separate from its bracket. While it’s loose, it’ll move around more, creating a clunking sound and making your driveshaft spin faster. When you press on the acceleration pedal, you might feel your car vibrating. This vibration is your engine working harder to keep up.
2. You Hear A Clunking, Screeching, or Grinding Noise Under Your Car
Another symptom of bad carrier bearings is a distinct grinding or spinning noise under your car. These noises are sometimes caused by worn-out internal bearings. It might also be the sound of your carrier bearings and u-joints getting bound up or meeting resistance while they turn.
Why Your Bearings and U-Joints Might Go Bad
*DIY Mechanic’s Note*: Grab some goggles and gloves before you stick your head under the car and start banging on and shaking stuff. A mask over your mouth and nose isn’t such a bad idea either. Rust is not very tasty.
1. Your Carrier Bearing Has Gotten Loose
Your driveshaft is positioned lengthwise along your car and sits between two other parts: your transfer case and your differential. Each driveshaft also comes with u-joints that help it move while your car’s operating. Most driveshafts have two u-joints, but cars with long wheelbases (the horizontal distance between your wheels) might have three of these joints.
Then there’s the carrier bearing, which gives the center of your driveshaft extra support. If the carrier bearing becomes loose, your driveshaft becomes unbalanced, which leaves it prone to bending while you’re accelerating and causes vibrations.
2. Your Carrier Bearings or U-Joints Are Rusted or Worn-Out
Your carrier bearing problems don’t occur on their own, there’s usually another issue with your driveshaft that caused a carrier bearing malfunction. It could be that your carrier bearings’ internal bearings have dried out or gotten worn. These faulty internal bearings can cause grinding or spinning noises while you’re driving.
You should also check your u-joints because corrosion can cause them to bind or freeze up. These joints can also dry out from lack of grease. If your u-joint is binding, it’ll make lots of vibrations, and these vibrations will destroy the rubber on your carrier bearing, causing it to loosen. The rubber on your carrier bearing will naturally break down over time, but the problem is made much worse by bad u-joints.
*DIY Mechanic’s Note*: Winter weather and road treatment for ice is the number one culprit for anything rusting or corroding on the undercarriage of your vehicle. I know it seems futile but washing your car with a good undercarriage spray, a few times during the winter months, will go a long way in preventing that rust and corrosion.
Check your carrier bearings and see if the center bearing rubber cushion is sticking out from the bracket seal, or if the bracket doesn’t feel secure. If you run into these problems, you need to replace your carrier bearing.
Diagnosing Bad Carrier Bearings And U-Joints By Yourself
If you want to check your carrier bearings and u-joints by yourself, follow these steps:
1. Remove Your Driveshaft
To remove your driveshaft, carefully remove the nuts from the bracket holding your carrier bearing in place.
2. Check Your Carrier Bearing for Damage
You can check your carrier bearing for cracks or damage. Try spinning the bearing and see if it makes a loud whirring noise. You can also wiggle the carrier bearing bracket and see if it moves around too much. Check the rubber to see if it’s rotting or cracked. If you notice any of these symptoms, you can now look to your u-joints for a possible cause.
3. Inspect Your U-Joints
Check your u-joints for tightness and binding. You can move the joints around and check if they’re tight. Also check the joints for rust and corrosion, which can be a cause of the tightness. You can also check for grease by removing the caps from the joints and looking at the roller bearings. If the bearings are dusty and the insides are red, the joints have dried up and are overheating, which means you’ll need replacement u-joints.
When you experience mechanical issues with your car or truck, whether it’s a corroded center support bearing, a bad u-joint, vehicle HVAC issues, or exhaust issues, PartsHawk.com is your one-stop-shop for all of your replacement auto parts. If you have questions or need help finding the right part for you, contact us to connect with one of our auto parts specialists.